Substrate treatment system, substrate transfer method and computer storage medium

ABSTRACT

An interface station of a coating and developing treatment system has: a cleaning unit cleaning at least a rear surface of a wafer before the wafer is transferred into an exposure apparatus; an inspection unit inspecting the rear surface of the cleaned wafer whether the wafer is exposable, before it is transferred into the exposure apparatus; wafer transfer mechanisms including arms transferring the wafer between the units and a wafer transfer control part controlling operations of the wafer transfer mechanisms. When it is determined that a state of the wafer becomes an exposable state by re-cleaning in the cleaning unit as a result of the inspection, the wafer transfer control part controls the wafer transfer mechanisms to transfer the wafer again to the cleaning unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/663,846 filed on Oct. 30, 2012, which is based upon and claims thebenefit of priority of Japanese Patent Application No. 2011-242333,filed in Japan on Nov. 4, 2011, and Japanese Patent Application No.2012-242336, filed in Japan on Nov. 4, 2011, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate treatment system performingtreatment on a substrate, a substrate transfer method in the substratetreatment system and a non-transitory computer storage medium.

2. Description of the Related Art

For example, in a photolithography process in manufacturing processes ofa semiconductor device, a series of treatments such as resist coatingtreatment of applying a resist solution onto a wafer to form a resistfilm, exposure processing of exposing the resist film to a predeterminedpattern, developing treatment of developing the exposed resist film andso on are sequentially performed, whereby a predetermined resist patternis formed on the wafer. The series of treatments are performed in acoating and developing treatment system being a substrate treatmentsystem in which various kinds of treatment units treating the wafer andtransfer units transferring the wafer are installed.

For example, a coating and developing treatment system 200conventionally includes a cassette station 201 for transferring acassette C in/out from/to the outside, a treatment station 202 in whicha plurality of treatment units performing various treatments such asresist coating treatment, developing treatment, and thermal treatmentare provided at the front and the back therein, and an interface station203 delivering a wafer between an exposure apparatus A provided outsidethe coating and developing treatment system 200 and adjacent thereto andthe treatment station 202, which are integrally provided as illustratedin FIG. 20.

In recent year, miniaturization of a circuit pattern to be formed on thewafer is further advanced and the defocus margin in exposure processingbecomes smaller. In association with that, it is required, as much aspossible, to prevent particles from being brought into the exposureapparatus A. In particular, the particles on the rear surface of thewafer is becoming a problem. Therefore, to reduce, as much as possible,the particles brought into the exposure apparatus A, a cleaning unit 210cleaning the rear surface of the wafer before it is transferred into theexposure apparatus A, an inspection unit 211 inspecting the cleanedwafer, a delivery unit 212 and wafer transfer apparatuses 213 providedat multiple tiers for delivering the wafer between the units 210 and 211are provided in the interface station 203 in some cases (JapaneseLaid-open Patent Publication No. 2008-135583).

SUMMARY OF THE INVENTION

Incidentally, in the above-described coating and developing treatmentsystem 200, the yield in the coating and developing treatment system 200further improves as the number of wafers determined to be abnormal inthe inspection unit 211 is smaller.

Review by the present inventors shows that even wafers determined to beabnormal in the inspection unit 211 include may wafers which will becomea state of being transferable into the exposure apparatus A byre-cleaning in the cleaning unit 210.

In the above-described coating and developing system 200 of the PatentDocument JP 2008-135583, however, the wafer determined to be abnormal iscollected into the cassette station 201, failing to improve the yield.

The present invention has been made in consideration of the above pointsand its object is to improve the yield of the substrate treatment in asubstrate treatment system having a function of cleaning a rear surfaceof a substrate before exposure.

To achieve the above object, the present invention is a substratetreatment system including a treatment station in which a plurality oftreatment units each treating a substrate, and an interface stationdelivering the substrate between the treatment station and an exposureapparatus provided outside, the interface station including: a cleaningunit cleaning at least a rear surface of the substrate before thesubstrate is transferred into the exposure apparatus; an inspection unitinspecting at least the rear surface of the cleaned substrate whetherthe substrate is exposable, before the substrate is transferred into theexposure apparatus; a substrate transfer mechanism including an armtransferring the substrate between the cleaning unit and the inspectionunit; and a substrate transfer control part controlling an operation ofthe substrate transfer mechanism, wherein when it is determined that astate of the substrate becomes an exposable state by re-cleaning in thecleaning unit as a result of the inspection in the inspection unit, thesubstrate transfer control part controls the substrate transfermechanism to transfer the substrate again to the cleaning unit.

According to the present invention, a substrate transfer control part isprovided which controls a substrate transfer mechanism, when it isdetermined that the substrate is in a state of being unexposable underthe existing condition but becoming exposable by re-cleaning in thecleaning unit as a result of inspection in the inspection unit of therear surface of the cleaned substrate, to transfer the substrate againto the cleaning unit. In this case, the re-cleaning of the substrate isperformed as necessary, so that even the substrate which has beendetermined to be unexposable in the prior art can be continuouslysubjected to substrate treatment. Accordingly, the number of substratesfor which the treatment is stopped on the way and which are collectedinto a cassette can be reduced as compared to the conventional coatingand developing treatment system in which the treatment for all of thesubstrates determined to be unexposable is stopped on the way and thesubstrates are collected into the cassette. Consequently, the yield ofthe substrate treatment by the substrate treatment system can beimproved.

The present invention according to another aspect is a substratetransfer method in a substrate treatment system including a treatmentstation in which a plurality of treatment units each treating asubstrate, and an interface station delivering the substrate between thetreatment station and an exposure apparatus provided outside, theinterface station including: a cleaning unit cleaning at least a rearsurface of the substrate before the substrate is transferred into theexposure apparatus; an inspection unit inspecting at least the rearsurface of the cleaned substrate whether the substrate is exposable,before the substrate is transferred into the exposure apparatus; and asubstrate transfer mechanism including an arm transferring the substratebetween the cleaning unit and the inspection unit, wherein when it isdetermined that a state of the substrate becomes an exposable state byre-cleaning in the cleaning unit as a result of the inspection in theinspection unit, the substrate is transferred again to the cleaningunit.

According to the present invention in yet another aspect is anon-transitory computer-readable storage medium storing a programrunning on a computer of a control unit controlling a substratetreatment system to cause the substrate treatment system to execute amethod of transferring a substrate, said substrate treatment systemcomprising a cleaning unit cleaning at least a rear surface of thesubstrate before the substrate is transferred into said exposureapparatus, an inspection unit inspecting at least the rear surface ofthe cleaned substrate whether the substrate is exposable, before thesubstrate is transferred into said exposure apparatus; and a substratetransfer mechanism including an arm transferring the substrate betweensaid cleaning unit and said inspection unit, wherein said programcontrol the substrate transfer mechanism when it is determined that astate of the substrate becomes an exposable state by re-cleaning in thecleaning unit as a result of the inspection in the inspection unit, thesubstrate is transferred again to the cleaning unit.

According to the present invention, it is possible to improve the yieldof the substrate treatment in a substrate treatment system having afunction of cleaning a rear surface of a substrate before exposure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating the outline of an internalconfiguration of a coating and developing treatment system according toan embodiment;

FIG. 2 is an explanatory view illustrating the outline of the internalconfiguration on the front side of the coating and developing treatmentsystem according to this embodiment;

FIG. 3 is an explanatory view illustrating the outline of the internalconfiguration on the back side of the coating and developing treatmentsystem according to this embodiment;

FIG. 4 is an explanatory view illustrating the outline of aconfiguration of an interface station according to this embodiment;

FIG. 5 is a plan view illustrating the outline of a configuration of acleaning unit;

FIG. 6 is a longitudinal sectional view illustrating the outline of theconfiguration of the cleaning unit;

FIG. 7 is an explanatory view illustrating the appearance in which awafer is delivered to the cleaning unit;

FIG. 8 is an explanatory view illustrating the state in which the waferhas been delivered to the cleaning unit;

FIG. 9 is an explanatory view illustrating the appearance in which thewafer is moved in the horizontal direction inside the cleaning unit;

FIG. 10 is an explanatory view illustrating the appearance in which thewafer is moved in the horizontal direction inside the cleaning unit;

FIG. 11 is an explanatory view illustrating the appearance in which anedge portion of the wafer is cleaned in the cleaning unit;

FIG. 12 is a longitudinal sectional view illustrating the outline of aconfiguration of an inspection unit;

FIG. 13 is a plan view illustrating the outline of a configuration of adehydration unit;

FIG. 14 is a longitudinal sectional view illustrating the outline of theconfiguration of the dehydration unit;

FIG. 15 is a flowchart illustrating main steps of wafer treatmentperformed in the coating and developing treatment system;

FIG. 16 is a longitudinal sectional view illustrating the outline of aconfiguration of a cleaning and inspection unit;

FIG. 17 is a transverse sectional view illustrating the outline of theconfiguration in the vicinity of a wafer cleaning part of the cleaningand inspection unit;

FIG. 18 is a longitudinal sectional view illustrating the outline of theconfiguration of the cleaning and inspection unit;

FIG. 19 is a longitudinal sectional view illustrating the outline of theconfiguration of a cleaning and inspection unit; and

FIG. 20 is an explanatory view illustrating the outline of aconfiguration of a conventional coating and developing treatment system.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described.FIG. 1 is an explanatory view illustrating the outline of an internalconfiguration of a coating and developing treatment system 1 as asubstrate treatment system according to this embodiment. FIG. 2 and FIG.3 are explanatory views illustrating the outline of the internalconfiguration of the coating and developing treatment system 1 from thefront side and the back side, respectively.

The coating and developing treatment system 1 has, as illustrated inFIG. 1, a configuration in which, for example, a cassette station 2to/from which a cassette C housing a plurality of wafers W therein istransferred in/out from/to the outside, a treatment station 3 includinga plurality of treatment units performing predetermined treatments onthe wafer W in the photolithography processing, and an interface station5 delivering the wafers W to/from an exposure apparatus 4, areintegrally connected. The coating and developing treatment system 1further has a control unit 6 performing control on various treatmentunits and so on.

The cassette station 2 is composed of, for example, a cassettetransfer-in/out section 10 and a wafer transfer section 11. The cassettetransfer-in/out section 10 is provided, for example, at the end on aY-direction negative direction (the left direction in FIG. 1) side inthe coating and developing treatment system 1. In the cassettetransfer-in/out section 10, a cassette mounting table 12 as a cassettemounting part is provided. On the cassette mounting table 12, forexample, four cassette mounting plates 13 are provided. The cassettemounting plates 13 are provided side by side in a line in an X-direction(an up and down direction in FIG. 1) being the horizontal direction. Onthe cassette mounting plates 13, cassettes C can be mounted when thecassettes C are transferred in/out from/to the outside of the coatingand developing treatment system 1.

In the wafer transfer section 11, a wafer transfer apparatus 21 movableon a transfer path 20 extending in the X-direction is provided asillustrated in FIG. 1. The wafer transfer apparatus 21 is movable alsoin the up and down direction and around the vertical axis (in aθ-direction) and can transfer the wafer W between the cassette C on eachof the cassette mounting plates 13 and a later-described delivery unitin a third block G3 in the treatment station 3.

In the treatment station 3 adjacent to the cassette station 2, aplurality of, for example, four blocks G1, G2, G3, G4 are provided eachof which includes various kinds of units. On the front side (anX-direction negative direction side in FIG. 1) in the treatment station3, the first block G1 is provided, and on the back side (an X-directionpositive direction side in FIG. 1) in the treatment station 3, thesecond block G2 is provided. Further, on the cassette station 2 side (aY-direction negative direction side in the in FIG. 1) in the treatmentstation 3, the third block G3 is provided, and on the interface station5 side (a Y-direction positive direction side in the in FIG. 1) in thetreatment station 3, the fourth block G4 is provided.

For example, in the first block G1, a plurality of solution treatmentunits, for example, a lower anti-reflection film forming unit 30 formingan anti-reflection film under a resist film of the wafer W (hereinafter,referred to as a “lower anti-reflection film”), a resist coating unit 31applying a resist solution onto the wafer W to form a resist film, anupper anti-reflection film forming unit 32 forming an anti-reflectionfilm on top of the resist film of the wafer W (hereinafter, referred toas an “upper anti-reflection film”), and a developing treatment unit 33performing developing treatment on the wafer W, are stacked at fourtiers from the bottom as illustrated in FIG. 2.

Each of the units 30 to 33 in the first block G1 has a plurality of cupsF each of which houses the wafer W therein during treatment in thehorizontal direction to be able to treat a plurality of wafers W inparallel.

For example, in the second block G2, as illustrated in FIG. 3, thermaltreatment units 40 each performing thermal treatment on the wafer W,adhesion units 41 as hydrophobic treatment apparatuses each performinghydrophobic treatment on the wafer W, and edge exposure units 42 eachexposing the outer peripheral portion of the wafer W are arranged one ontop of the other in the vertical direction and side by side in thehorizontal direction as illustrated in FIG. 3. The thermal treatmentunit 40 has a thermal plate that mounts and heats the wafer W thereonand a cooling plate that mounts and cools the wafer W thereon so as tobe able to perform both heat treatment and cooling treatment. Note thatthe numbers and the arrangement of the thermal treatment units 40,adhesion units 41, and edge exposure units 42 can be arbitrarilyselected.

For example, in the third block G3, a plurality of delivery units 50,51, 52, 53, 54, 55, 56 are provided in order from the bottom. Further,in the fourth block G4, a plurality of delivery units 60, 61, 62 areprovided in order from the bottom.

A wafer transfer region D is formed in a region surrounded by the firstblock G1 to the fourth block G4 as illustrated in FIG. 1. In the wafertransfer region D, for example, a plurality of, for example, three wafertransfer apparatuses 70 are provided. The wafer transfer apparatuses 70have the same structure.

The wafer transfer apparatus 70 has a transfer arm 70 a that is movable,for example, in the Y-direction, a forward and backward direction, theθ-direction, and the up and down direction. The transfer arm 70 a canmove in the wafer transfer region D and transfer the wafer W to apredetermined unit in the first block G1, the second block G2, the thirdblock G3, and the fourth block G4 therearound. A plurality of wafertransfer apparatuses 70 are provided one above top of the other asillustrated in FIG. 3 and can transfer the wafers W, for example, topredetermined units at the similar levels in the blocks G1 to G4.

Further, in the wafer transfer region D, a shuttle transfer apparatus 80linearly transferring the wafer W between the third block G3 and thefourth block G4 is provided.

The shuttle transfer apparatus 80 is configured to be linearly movable,for example, in the Y-direction in FIG. 3. The shuttle transferapparatus 80 can move in the Y-direction while supporting the wafer Wand transfer the wafer W between the delivery unit 52 in the third blockG3 and the delivery unit 62 in the fourth block G4.

As illustrated in FIG. 1, a wafer transfer apparatus 90 is provided onthe X-direction positive direction side of the third block G3. The wafertransfer apparatus 90 has a transfer arm 90 a that is movable, forexample, in the forward and backward direction, the θ-direction, and theup and down direction. The wafer transfer apparatus 90 can move up anddown while supporting the wafer W to transfer the wafer W to each of thedelivery units in the third block G3.

On the X-direction positive direction side of the fourth block G4, awafer transfer apparatus 85 is provided. The wafer transfer apparatus 85has a transfer arm 85 a that is movable, for example, in the forward andbackward direction, the θ-direction, and the up and down direction. Thewafer transfer apparatus 85 can move up and down while supporting thewafer W to transfer the wafer W to the interface station 5.

In the interface station 5, three blocks G5, G6, G7 each includingvarious units are provided. For example, on the front side (anX-direction negative direction side in FIG. 1) in the interface station5, the fifth block G5 is provided. The sixth block G6 is provided on theback side (the X-direction positive direction side in FIG. 1) in theinterface station 5. Further, the seventh block G7 is provided in aregion between the fifth block G5 and the sixth block G6.

For example, in the fifth block G05, cleaning units 100 each cleaningthe rear surface of the wafer W before the wafer W is transferred intothe exposure apparatus 4 are provided, for example, at four tiersstacked in the up and down direction as illustrated in FIG. 4.

In the sixth block G6, inspection units 101 each inspecting whether therear surface of the wafer W cleaned in the cleaning unit 100 is in astate of allowing exposure in the exposure apparatus 4 before the waferW is transferred into the exposure apparatus 4, and dehydration units102 each removing moisture adhering to the wafer W after it is cleanedin the cleaning unit 100, are provided stacked at two tiers each in thisorder from the bottom to the top. Note that FIG. 4 is an explanatoryview illustrating the outline of the internal configuration of theinterface station 5 when the interface station 5 is seen from thecassette station 2 side.

In the seventh block G7, delivery units 110 each delivering the wafer Wto/from the treatment station 3 via the wafer transfer apparatus 85,buffer units 111 as buffer housing parts each temporarily housing thewafer W inspected in the inspection unit 101, and temperature regulationunits 112 as temperature regulation mechanisms each regulating thetemperature of the inspected wafer W to a predetermined temperaturebefore it is transferred into the exposure apparatus 4, are provided atmultiple tiers in the up and down direction. More specifically, in anupper part of the seventh block G7, the delivery units 110 and thebuffer units 111 are arranged alternately stacked at three tiers each inthis order from the top. In a lower part of the seventh block G7, thedelivery units 110 and the temperature regulation units 112 are arrangedalternately stacked at two tiers each in this order from the top. Thetemperature regulation unit 112 has a temperature regulation plateincluding a temperature regulation member such as a Peliter element andthus can temperature-regulate the wafer W mounted on the temperatureregulation plate to a predetermined temperature, for example, roomtemperature.

In a region between the fifth block G5 and the seventh block G7 andadjacent to the fifth block G5, a wafer transfer mechanism 120 as asubstrate transfer mechanism is provided. The wafer transfer mechanism120 has a first transfer arm 121 and a second transfer arm 122 as aplurality of transfer arms. Each of the transfer arms 121, 122 isconfigured to be movable, for example, in the forward and backwarddirection, the θ-direction, and the up and down direction. Each of thetransfer arms 121, 122 can thus move up and down while supporting thewafer W to transfer the wafer W between the units in the blocks G5, G7.

In a region between the sixth block G6 and the seventh block G7 andadjacent to the sixth block G6, a wafer transfer mechanism 130 isprovided. The wafer transfer mechanism 130 is provided with a thirdtransfer arm 123 and a fourth transfer arm 124. Each of the transferarms 123, 124 is configured to be movable, for example, in the forwardand backward direction, the θ-direction, and the up and down direction.Each of the transfer arms 123, 124 can thus move up and down whilesupporting the wafer W to transfer the wafer W between the units in theblock G6, between the sixth block G6 and the seventh block G7, andbetween the sixth block G6 and the exposure apparatus 4. Note that asthe wafer transfer mechanism 120, the plurality of independently movingtransfer arms 121, 122 are illustrated in FIG. 4, but one transfer armprovided with a plurality of, for example, two sets of tweezers holdingthe wafer W may be used in place of the plurality of transfer arms. Thisalso applies to the wafer transfer mechanism 130.

The transfer by the wafer transfer mechanisms 120, 130 is controlled bya wafer transfer control part 125 as a substrate transfer control partof the control unit 6 illustrated in FIG. 1. The wafer transfer controlpart 125 controls the wafer transfer mechanism 120 so that the firsttransfer arm 121 transfers the wafer W between the cleaning unit 100 andthe delivery unit 110 and the second transfer arm 122 transfers thecleaned wafer W to the delivery unit 110. The wafer transfer controlpart 125 further controls the wafer transfer mechanism 130 so that thethird transfer arm 123 performs transfer of the wafer W cleaned in thecleaning unit 100 from the delivery unit 110 to the dehydration unit102, transfer from the dehydration unit 102 to the inspection unit 101,transfer from the inspection unit 101 to the buffer unit 111, andtransfer from the buffer unit 111 to the temperature regulation unit112.

The wafer transfer control part 125 also controls the wafer transfermechanism 130 so that the fourth transfer arm 124 transfers the wafer Wbetween the temperature regulation unit 112 and the delivery unit 110and the exposure apparatus 4. Note that the wafer transfer control part125 also controls the operations of the other wafer transfer apparatusesin the coating and developing treatment system 1.

Next, the configuration of the cleaning unit 100 will be described. FIG.5 is a plan view illustrating the outline of the configuration of thecleaning unit 100, and FIG. 6 is a longitudinal sectional viewillustrating the outline of the configuration of the cleaning unit 100.

The cleaning unit 100 has two suction pads 140, 140 horizontallysuction-holding the wafer W transferred via the first transfer arm 121,a spin chuck 141 horizontally suction-holding the wafer W received fromthe suction pads 140, a brush 142 cleaning the rear surface of the waferW, and a casing 143 having an upper surface open.

As illustrated in FIG. 5, the two suction pads 140, 140 are providedsubstantially parallel to each other with the spin chuck 141 interveningtherebetween in a plan view to be able to hold the edge portion of therear surface of the wafer W. Each of the suction pads 140, 140 issupported at its both ends by a frame body 144 movable in the horizontaldirection and the up and down direction by a drive mechanism (notillustrated).

On an upper surface of the frame body 144, an upper cup 145 is provided.In an upper surface of the upper cup 145, an opening 145 a with adiameter larger than the diameter of the wafer W is formed so that thewafer W is delivered between the first transfer arm 121 and the suctionpads 140 through the opening 145 a.

As illustrated in FIG. 6, the spin chuck 141 is connected to a drivemechanism 151 via a shaft 150 so that the spin chuck 141 is configuredto freely rotate and rise and lower by means of the drive mechanism 151.

Around the spin chuck 141, raising and lowering pins 152 are providedwhich freely rise and lower by means of a raising and lowering mechanism(not illustrated).

The brush 142 is configured, for example, by bundling many plasticfibers in a column shape, and is supported by a support body 153. Thesupport body 153 is connected to a drive mechanism 154. The drivemechanism 154 is connected to the casing 143 and can horizontally movein the X-direction in FIG. 5 and along the casing 143. Accordingly, bymoving the drive mechanism 154 in the X-direction, the brush 142 can bemoved in the X-direction in FIG. 5 via the support body 153. The brush142 is configured to freely rotate by means of a drive mechanism (notillustrated) built in the support body 153 so that particles adhering tothe rear surface of the wafer W can be removed by rotating the brush 142with its upper surface pressed against the rear surface of the wafer Wand sliding the brush 142 on the rear surface of the wafer W.

Further, at the tip end of the support body 153, a cleaning solutionnozzle 153 a supplying a cleaning solution for washing away theparticles removed by the brush, and a purge nozzle 153 b supplying gassuch as nitrogen for drying the cleaning solution adhering to the rearsurface of the wafer W after cleaning, are provided.

At the bottom of the casing 143, a drain pipe 160 draining the cleaningsolution and an exhaust pipe 161 forming downward airflow in thecleaning unit 100 and exhausting the airflow are provided.

Next, the cleaning of the wafer W in the cleaning unit 100 will bedescribed. For the cleaning of the wafer W, the wafer W is transferredby the first transfer arm 121 to above the upper cup 145 as illustratedin FIG. 7. Then, the raising and pins 152 are raised and the wafer W isdelivered to the raising and lowering pins 152. In this event, thesuction pads 140 are waiting with the upper surfaces thereof located ata position higher than the upper surface of the brush 142, and the spinchuck 141 is retracted to a position lower than the upper surface of thebrush 142. Thereafter, the raising and lowering pins 152 are lowered,whereby the wafer W is delivered to and held on the suction pads 140 asillustrated in FIG. 8.

Subsequently, the frame body 144 is horizontally moved so that, forexample, the brush 142 is located in a region corresponding to thecenter part of the rear surface of the wafer W with the wafer Wsuction-held by the suction pads 140 as illustrated in FIG. 9. Then, thesuction pads 140 are lowered and the rear surface of the wafer W ispressed against the upper surface of the brush 142.

Then, the cleaning solution is supplied from the cleaning solutionnozzle 153 a and the brush 142 is rotated to clean the center part ofthe rear surface of the wafer W. In this event, the support body 153reciprocates in the X-direction in FIG. 5 and the frame body 144reciprocates in the Y-direction, whereby the center part of the rearsurface of the wafer W is evenly cleaned.

After the cleaning of the center part of the rear surface of the wafer Wis finished, the frame body 144 is horizontally moved so that the centerof the wafer W is aligned with the center of the spin chuck 141 in aplan view as illustrated in FIG. 10. Then, the spin chuck 141 is raised,whereby the wafer W is delivered from the suction pads 140 to the spinchuck 141.

Thereafter, as illustrated in FIG. 11, the wafer W is rotated with thebrush 142 pressed against the rear surface of the wafer W and the brush142 is slid in the X-direction via the support body 153, whereby theedge portion of the rear surface of the wafer W is cleaned. This removesthe particles on the entire rear surface of the wafer W.

After the cleaning of the rear surface of the wafer W is completed, therotation of the brush 142 and the supply of the cleaning solution arestopped and the spin chuck 141 is rotated at a high speed, whereby thecleaning solution adhering to the rear surface of the wafer W isspin-dried. In this event, the purge by the purge nozzle 153 b isperformed in parallel.

After the drying is finished, the wafer W is delivered to the secondtransfer arm 122 in the order reverse to that when it is transferred tothe cleaning unit 100.

Next, the configuration of the inspection unit 101 will be described.FIG. 12 is a longitudinal sectional view illustrating the outline of theconfiguration of the inspection unit 101.

The inspection unit 101 has a casing 170 in which a holding arm 171holding the wafer W with at least the rear surface of the wafer W opendirected downward, a light source 172 applying parallel light rays inline shape to the rear surface of the wafer W held by the holding arm171, and a camera 173 picking up an image of the light applied to therear surface of the wafer W are provided. The holding arm 171 isconfigured to be movable in the horizontal direction by means of a drivemechanism (not illustrated).

A locking part 171 a projecting downward is formed at the tip end of theholding arm 171, and a movable holding part 171 b movable in thedirection of the diameter of the wafer W by means of a not-illustrateddrive mechanism is provided on the lower surface of the holding arm 171.The holding arm 171 can hold, by the locking part 171 a and the movableholding part 171 b, the wafer W delivered from the third transfer arm123 entering the casing 170 through an opening 170 a of the casing 170and hold the wafer W with the rear surface directed downward.

The light source 172 is disposed below the holding arm 171 to apply thelight rays at a predetermined angle of θ with respect to the rearsurface of the wafer W. The camera 173 is disposed below the holding arm171 in a state of being tilted at the predetermined angle of θ,similarly to the light source 172, with respect to the rear surface ofthe wafer W to pick up an image of the light rays applied to the rearsurface of the wafer W.

The light source 172 and the camera 173 are adjustable in applicationangle and imaging angle by means of a not-illustrated tuning mechanism.This enables observation of the particles, which cannot be observed bylight rays applied at a certain angle, by applying the light rays at adifferent angle.

In the inspection unit 101, the holding arm 171 moves in the horizontaldirection while holding the wafer W and the camera 173 continuouslypicks up an image of the light rays applied to the rear surface of thewafer W to thereby pick up an image of the entire rear surface of thewafer W. The image picked up by the camera 173 is inputted into thecontrol unit 6, and the control unit 6 determines whether the state ofthe rear surface of the wafer W allows exposure in the exposureapparatus 4. Note that the control unit 6 determines whether to performexposure on the wafer W in the exposure apparatus 4 based on the numberand an adhesion range of particles adhering to the rear surface of thewafer W, or the height and size of the particles.

Next, the configuration of the dehydration unit 102 will be described.FIG. 13 is a plan view illustrating the outline of the configuration ofthe dehydration unit 102, and FIG. 14 is a longitudinal sectional viewillustrating the outline of the configuration of the dehydration unit102.

The dehydration unit 102 has a treatment container 180 in whichdehydration treatment is performed on the wafer W, holding members 181holding the outer peripheral portion of the rear surface of the wafer W,and a raising and lowering mechanism 183 raising and lowering theholding members 181 in the up and down direction via a shaft 182.

A plurality of, four in this embodiment, holding members 181 are eachconcentrically formed in an almost arc shape in a plan view asillustrated, for example, in FIG. 13. The holding member 181 has across-sectional shape in an almost U-shape as illustrated in FIG. 14. Anupper end part 181 a on the outer peripheral side of the holding member181 is formed to be higher than an upper end part 181 b on the innerperipheral side. Thus, a part of the holding member 181 on the outerperipheral side functions as a guide preventing the wafer W from fallingoff when the wafer W is held by the upper end part 181 b on the innerperipheral side.

For delivery of the wafer W between each holding member 181 and thethird transfer arm 123, the third transfer arm 123 enters through ashutter 180 a of the treatment container 180, for example, asillustrated in FIG. 13, and the third transfer arm 123 is moved so thatthe center part of the wafer W held by the third transfer arm 123 isaligned with the center of the arcs formed by the plurality of holdingmembers 181. Then, in this state, the raising and lowering mechanism 183raised the holding members 181. Thereby, the wafer W is delivered fromthe third transfer arm 123 to the holding members 181. Thereafter, thethird transfer arm 123 is retracted to the outside of the treatmentcontainer 180. Note that the delivery of the wafer W between the thirdtransfer arm 123 and the holding members 181 may be performed, forexample, by raising and lowering the third transfer arm 123.

At the bottom of the treatment container 180, an exhaust pipe 185connected to an exhaust mechanism 184 and a purge pipe 186 purging theinside of the treatment container 180 by feeding, for example, anitrogen gas into the treatment container 180 are provided. To the purgepipe 186, a gas supply source 187 supplying the nitrogen gas isconnected.

For performing the dehydration treatment on the wafer W in thedehydration unit 102, the wafer W is first transferred by the thirdtransfer arm 123 into the treatment container 180, and the wafer W isthen delivered to the holding members 181. Thereafter, the thirdtransfer arm 123 is retracted to the outside of the treatment container180, and the shutter 180 a is closed. Subsequently, the exhaustmechanism 184 reduces the pressure inside the treatment container 180.This vaporizes the moisture adhering to the wafer W and thereby performsthe dehydration treatment on the wafer W.

After the dehydration treatment on the wafer W is finished, purge andincrease in pressure inside the treatment container 180 are performedthrough the purge pipe 186. Thereafter, the shutter 180 a is opened, andthe wafer W is transferred by the third transfer arm 123 to theinspection unit 101.

The control unit 6 is composed of a computer including, for example, aCPU and a memory. In the control unit 6, a treatment recipe in whichcontents of the wafer treatment in the various treatment units in thecoating and developing treatment system 1 and the transfer route of eachwafer W are stored as a program, for example, in the memory. Byexecuting the program, the control unit 6 controls the various treatmentunits in the coating and developing treatment system 1, and theoperations of the wafer transfer mechanism 120 and the wafer transferapparatuses by the above-described wafer transfer control part 125, tothereby control the various treatments and transfer of the wafers W inthe coating and developing treatment system 1. Note that the program maybe the one that is stored, for example, in a computer-readable storagemedium H such as a computer-readable hard disk (HD), flexible disk (FD),compact disk (CD), magneto-optical disk (MO), or memory card, andinstalled from the storage medium H into the control unit 6.

In the coating and developing treatment system 1 configured as describedabove, for example, the following wafer treatment is performed. FIG. 15is a flowchart illustrating an example of main steps of the wafertreatment.

For the treatment on the wafer W, the cassette C housing a plurality ofwafers W therein is first mounted on a predetermined cassette mountingplate 13 in the transfer-in/out section 10. Then, the wafers W in thecassette C are successively taken out by the wafer transfer apparatus 21and transferred, for example, to the delivery unit 53 in the third blockG3 in the treatment station 3.

Next, the wafer W is transferred by the wafer transfer apparatus 70 tothe thermal treatment unit 40 in the second block G2 andtemperature-regulated (Step S1 in FIG. 15). The wafer W is thentransferred by the wafer transfer apparatus 70, for example, to thelower anti-reflection film forming unit 30 in the first block G1, wherea lower anti-reflection film is formed on the wafer W (Step S2 in FIG.15). The wafer W is then transferred to the thermal treatment unit 40 inthe second block G2 and subjected to heat treatment. The wafer W is thenreturned to the delivery unit 53 in the third block G3.

The wafer W is then transferred by the wafer transfer apparatus 90 tothe delivery unit 54 in the third block G3. The wafer W is thentransferred by the wafer transfer apparatus 70 to the adhesion unit 41in the second block G2 and subjected to adhesion treatment (Step S3 inFIG. 15). The wafer W is then returned by the wafer transfer apparatus70 to the resist coating unit 31, where a resist film is formed on thewafer W (Step S4 in FIG. 15).

The wafer W is then transferred by the wafer transfer apparatus 70 tothe thermal treatment unit 40 and subjected to pre-baking treatment(Step S5 in FIG. 15). Then, the wafer W is transferred by the wafertransfer apparatus 70 to the delivery unit 55 in the third block G3.

Subsequently, the wafer W is transferred by the wafer transfer apparatus70 to the upper anti-reflection film forming unit 32, where an upperanti-reflection film is formed on the wafer W (Step S6 in FIG. 15). Thewafer W is then transferred by the wafer transfer apparatus 70 to thethermal treatment unit 40 and heated and temperature-regulated. Thewafer W is then transferred to the edge exposure unit 42 and subjectedto edge exposure processing (Step S7 in FIG. 15).

The wafer W is then transferred by the wafer transfer apparatus 70 tothe delivery unit 56 in the third block G3.

The wafer W is then transferred by the wafer transfer apparatus 90 tothe delivery unit 52 and transferred by the shuttle transfer apparatus80 to the delivery unit 62 in the fourth block G4.

The wafer W is then transferred by the wafer transfer apparatus 85 tothe delivery unit 110 in the seventh block G7. The wafer W is thentransferred by the first transfer arm 121 to the cleaning unit 100, inwhich the rear surface of the wafer W is cleaned (Step S8 in FIG. 15).

The wafer W whose rear surface has been cleaned is transferred by thesecond transfer arm 122 to the delivery unit 110 in the seventh blockG7. The wafer W is then transferred by the third transfer arm 123 to thedehydration unit 102 and subjected to dehydration treatment (Step S9 inFIG. 15).

The wafer W which has been subjected to the dehydration treatment istransferred by the third transfer arm 123 to the inspection unit 101, inwhich the rear surface of the wafer W is inspected (Step S10 in FIG.15). The wafer W is then transferred by the third transfer arm 123 tothe buffer unit 111 and temporarily housed in the buffer unit 111 untilthe inspection result of the wafer W in the inspection unit 101 isavailable.

After the inspection result in the inspection unit 101 is available, thewafer transfer control part 125 controls the wafer transfer mechanism120 based on a predetermined rule to transfer the wafer W. Morespecifically, as a result of the inspection in the inspection unit 101,when it is determined that the wafer W is in a state of being exposablein the exposure apparatus 4, the wafer W is transferred by the thirdtransfer arm 123 to the temperature regulation unit 112 and thentransferred by the fourth transfer arm 124 to the exposure apparatus 4.As a result of the inspection, when it is determined that the wafer W isin a state of being unexposable in the exposure apparatus 4, thesubsequent treatments on the wafer W are stopped and the wafer W istransferred by the third transfer arm 123 to the delivery unit 110.Thereafter, the wafer W for which the subsequent treatments are stoppedis transferred by the wafer transfer apparatus 85 to the treatmentstation 3, and then collected into a cassette C on a predeterminedcassette mounting plate 13 (Step S11 in FIG. 15). Note that the routefor collecting the wafer W determined to be unexposable may be a routeusing, for example, the shuttle transfer apparatus 80 or a route forcollecting the wafer W via the tier of the developing treatment unit 33in the first block G1. The reason why the tier of the developingtreatment unit 33 is used is that the transfer direction of the exposedwafer W at the tier of the developing treatment unit 33 is the directionfrom the exposure apparatus 4 to the cassette station 2 side as with thetransfer direction of the wafer W determined to be unexposable, andtherefore the wafer W determined to be unexposable can be transferredwithout interfering with the transfer of normal wafers W.

As a result of the inspection, when it is determined that the wafer W isin a state of being unexposable under the existing condition butbecoming exposable in the exposure apparatus 4 by re-cleaning in thecleaning unit 100, the wafer W is delivered by the third transfer arm123 to the delivery unit 110 and transferred by the first transfer arm121 again to the cleaning unit 100. The wafer W re-cleaned in thecleaning unit 100 is then transferred again to the inspection unit 101.Thereafter, when the wafer W is determined to be exposable in theinspection unit 101, the wafer W is transferred by the third transferarm 123 to the temperature regulation unit 112, and then transferred bythe wafer transfer mechanism 130 to the exposure apparatus 4 andsubjected to exposure processing (Step S12 in FIG. 15).

The wafer W which has been subjected to the exposure processing istransferred by the fourth transfer arm 124 to the delivery unit 110 inthe seventh block G7. The wafer W is then transferred by the wafertransfer apparatus 85 to the delivery unit 40 in the fourth block G4.The wafer W is then transferred by the wafer transfer apparatus 70 tothe thermal treatment unit 40 and subjected to post-exposure bakingtreatment (Step S13 in FIG. 15). The wafer W is then transferred by thewafer transfer apparatus 70 to the developing treatment unit 33 andsubjected to developing treatment (Step S14 in FIG. 15). After thedevelopment, the wafer W is transferred by the wafer transfer apparatus70 to the thermal treatment unit 40 and subjected to post-bakingtreatment (Step S15 in FIG. 15).

The wafer W is then transferred by the wafer transfer apparatus 70 tothe delivery unit 50 in the third block G3, and then transferred by thewafer transfer apparatus 21 in the cassette station 2 to the cassette Con a predetermined cassette mounting plate 13. Thus, a series ofphotolithography processes end.

According to this embodiment, as a result of the inspection of thecleaned wafer W in the inspection unit 101, when it is determined thatthe wafer W is in a state of being unexposable under the existingcondition but becoming exposable by re-cleaning in the cleaning unit100, the wafer transfer control part 125 controls the wafer transfermechanism 120 to transfer the wafer W again to the cleaning unit 100. Inthis case, the number of wafers W for which the subsequent treatmentsare stopped and which are collected into the cassette C can be reducedas compared to the conventional coating and developing treatment system200 in which the subsequent treatments for all of the wafers Wdetermined to be unexposable are stopped and the wafers W are collectedinto the cassette C. Consequently, the yield of the treatment on thewafer W by the coating and developing treatment system 1 can beincreased.

Further, since the buffer unit 111 for temporarily housing the wafer Winspected in the inspection unit 101 is provided, the inspected wafer Wcan be kept waiting in the buffer unit Ill until the inspection resultin the inspection unit 101 is available. If the wafer W is transferredwithout inspection result being available, a need to change the transferdestination of the wafer W during transfer may arise depending on theinspection result available afterward to greatly influence the transferof the wafer W. However, such influence is never caused by keeping theinspected wafer W in the buffer unit 111 until the inspection result isavailable, because the wafer W can be transferred after decision of thetransfer destination.

Note that the time period for keeping in the buffer unit 111 the wafer Winspected in the inspection unit 101 does not need to be terminated atthe time when the inspection result of the wafer W is available, but thewafer W may be kept waiting for a longer time. For example, in the casewhere a plurality of inspected wafers W are housed in the buffer unit111, when the inspection result of a wafer W whose inspection result isavailable first is the to above-described “re-cleaning,” the inspectionresult of another wafer W housed in the buffer unit 111 may be availableduring the process of the former wafer W being re-cleaned in thecleaning unit 100. In this case, if the next wafer W whose inspectionresult has been available is transferred to the exposure apparatus 4side, the latter wafer W will be transferred to the exposure apparatus 4passing the former wafer W to be re-cleaned. In this case, the latterwafer W will be transferred to the exposure apparatus 4 in an orderdifferent from the transfer schedule for the latter wafer W set in thetreatment recipe, for example, for each lot, thus possibly causing atransfer error because the exposure apparatus 4 cannot recognize thelatter wafer W.

Accordingly, when an arbitrary wafer W is determination to require“re-cleaning” as described above, it is preferable to keep the nextwafer W in the buffer unit 111 until the arbitrary wafer W is inspectedagain in the inspection unit 101 after the re-cleaning and theinspection result of the re-cleaning is available after the arbitrarywafer W is housed in the buffer unit 111. By adjusting the time forkeeping the wafer W waiting in the buffer unit 111 as described above,the wafer W can be transferred in a predetermined order even in the caseof “re-cleaning.” Note that the buffer unit 111 may be configured to beable to house a plurality of wafers W, for example, at multiple tiers.In this case, for example, when a wafer W in the buffer unit 111 isdetermined to be unexposable, the wafer W is housed in the buffer unit111 until the timing when the wafer W does not influence any longer theschedule of the wafer transfer by the wafer transfer mechanism 120,thereby making it possible to collect the wafer W without influencingthe transfer schedule. It is also adoptable to keep, for example, aplurality of wafers W determined to be exposable waiting in the bufferunit 111. In this case, the exposable wafers W kept waiting aretransferred to the exposure apparatus 4 during the time when the wafer Wdetermined to require “re-cleaning” is re-cleaned, thereby ensuring thewafer W to be transferred to the exposure apparatus 4 at all times toprevent the exposure apparatus 4 from being kept waiting.

In the above embodiment, since the cleaned wafer W is transferred byeach transfer arm 122, 123, 124 to each unit, it is possible to suppresscontamination of each transfer arm 122, 123, 124 transferring thecleaned wafer W with particles adhering to the rear surface of the waferW. As a result, it is possible to keep each transfer arm 122, 123, 124clean and to reduce the possibility that the rear surface of the wafer Wis contaminated with particles adhering to each transfer arm 122, 123,124 when the cleaned wafer W is transferred.

Note that the case where, for example, it is determined that the wafer Wis in a state of being unexposable in the exposure apparatus 4 as aresult of the inspection by the inspection unit 101 shows that thesecond transfer arm 122 and the third transfer arm 123 have transferredthe wafer W with particles adhering to the rear surface. Then, theparticles adhering to the wafer W may adhere to each transfer arm 122,123 and contaminate the rear surface of the wafer W to be transferrednext. Accordingly, when it is determined that the wafer W is in a stateof being unexposable in the exposure apparatus 4 as a result of theinspection in the inspection unit 101 or becoming exposable byre-cleaning, the second transfer arm 122 and the third transfer arm 123may be cleaned after the transfer of that wafer W. The cleaning of thesecond transfer arm 122 may be performed, for example, in the cleaningunit 100. In this case, the brush 142 in the cleaning unit 100 may beconfigured to be freely vertically reversed so that the upper surface ofthe second transfer arm 122 which has entered the cleaning unit 100 iscleaned with the reversed brush 142. Further, separately from thecleaning unit 100, another cleaning unit as an arm cleaning mechanismcleaning the second transfer arm 122 may be provided in the fifth blockG5 or the seventh bock G7. Note that when cleaning the third transferarm 123, another cleaning unit may be provided in the sixth block G6 orthe seventh block G7. Further, a cleaning mechanism for the transferarms 122, 123 may be provided in the buffer unit 111.

Though the cleaning unit 100 is arranged, for example, on the front sideand the inspection unit 101 and the dehydration unit 102 are arranged onthe back side in the coating and developing treatment system 1 in theabove embodiment, for example, the cleaning unit 100 and the dehydrationunit 102 may be arranged on the front side in the interface station 5,namely, provided at multiple tiers in the fifth block G5, and only theinspection unit 101 may be provided in the sixth block G6. This canminimize the number of times of the cleaned wafer W coming into contactwith the transfer arm. In other words, in the case where the cleaningunit 100 and the dehydration unit 102 are provided separately on thefront side and the back side, for transferring the wafer W from thecleaning unit 100 to the dehydration unit 102, it is necessary totransfer the wafer W first from the cleaning unit 100 to the deliveryunit 110 and then transfer the wafer W from the delivery unit 110 to thedehydration unit 102. In this case, the rear surface of the cleanedwafer W comes into contact with the transfer arms 122, 123 of the wafertransfer mechanisms 120, 130 at least one time each. In contrast, thearrangement of the cleaning unit 100 and the dehydration unit 102 in theup and down direction eliminates the necessity of passage through thedelivery unit 110 and therefore reduces the number of contact timesbetween the wafer W and the second transfer arm 122 of the wafertransfer mechanism 120 to one. As a result, the possibility that therear surface of the wafer W is contaminated with the particles adheringto the wafer transfer mechanism 120 can be reduced as compared to theprior art.

Further, the cleaning unit 100 and the inspection unit 101 may bearranged on the front side in the interface station 5, namely, providedat multiple tiers in the fifth block G5, and only the dehydration unit102 may be provided in the sixth block G6. The arrangement of only thedehydration unit 102 on the back side ensures, on the back side, theinstallation location for large-sized and heavy devices such as theexhaust mechanism 184 and the treatment container 180 which are providedin association with the dehydration unit 102.

Note that though the dehydration unit 102 is provided in the interfacestation 5 in the above embodiment, the dehydration unit 102 does notalways need to be provided in the present invention, and whether toinstall the dehydration unit 102 can be arbitrarily selected.

Further, provision of the plurality of transfer arms 121, 122, 123, 124in the wafer transfer mechanisms 120, 130 makes it possible to even thenumber of steps of transfer by the transfer arms 121, 122, 123, 124 soas to facilitate the management of the transfer time of the wafer W.

Though the temperature regulation is performed on the wafer W by thetemperature regulation unit 112 before the wafer W is transferred to theexposure apparatus 4 in the above embodiment, a temperature regulationmechanism regulating, for example, the temperature of the atmosphere inthe inspection unit 101 to a predetermined temperature may be providedin the inspection unit 101 to perform temperature regulation on thewafer W during the time when the wafer W is being inspected in theinspection unit 101. This can reduce the treatment time in thetemperature regulation unit 112 and the transfer time to the temperatureregulation unit 112, thereby improving the throughput of the coating anddeveloping treatment system 1.

Though the cleaning unit 100 and the inspection unit 101 are separatelyprovided in the above embodiment, the cleaning unit 100 and theinspection unit 101 may be provided in the same casing. In a concreteexample in this case, a cleaning and inspection unit 310 is used inwhich a wafer cleaning part 300 cleaning the rear surface of the waferW, a wafer inspection part 301 inspecting the cleaned wafer W before thewafer W is transferred into the exposure apparatus 4, and a transfermeans 302 transferring the wafer W between the wafer cleaning part 300and the wafer inspection part 301 are housed in one casing 303 asillustrates in FIG. 16, FIG. 17. Note that the devices given the samenumerals as those of the devices constituting the already-describedcleaning unit 100 and inspection unit 101 in the drawings have the sameconfigurations and therefore the description thereof will be omitted.Further, the arrangement of the cleaning and inspection unit 310 in theinterface station 5 is arbitrarily set in consideration of the transferorder and the throughput of the wafer W and is thus not particularlylimited.

As illustrated in FIG. 16, the wafer cleaning part 300 and the waferinspection part 301 are arranged in this order from the bottom to thetop in the casing 303. In a region between the wafer cleaning part 300and the wafer inspection part 301, namely, above the wafer cleaning part300 and below the wafer inspection part 301, a waiting and mountingtable 320 is arranged which temporarily keeps the wafer W inspected inthe wafer inspection part 301 waiting thereon.

The transfer means 302 includes a transfer arm 302 a in an almostU-shape having a tip branched off into two parts as illustrated in FIG.17. At the end of the transfer arm 302 a, an arm drive mechanism 302 bmoving the transfer arm 302 a in the forward and backward direction isprovided. The arm drive mechanism 302 b is supported by a base 302 c.

In the base 302 c, a drive mechanism (not illustrated) is built whichfreely moves the base 302 c in the θ-direction and the up and downdirection along a raising and lowering rail 302 d provided to extend inthe vertical direction. Thus, the transfer arm 302 a is configured to bemovable in the forward and backward direction, the θ-direction, and theup and down direction and can move up and down while holding the wafer Wto transfer the wafer W between the wafer cleaning part 300 and thewafer inspection part 301.

The waiting and mounting table 320 has raising and lowering pins (notillustrated) built therein and can deliver the wafer W through use ofthe raising and lowering pins to/from the transfer arm 302 a and eachtransfer arm in the interface station 5.

In the cleaning and inspection unit 310, the cleaning of the rearsurface of the wafer W and the spin-drying of the cleaning solution areperformed first at the wafer cleaning part 300. After the spin-drying isfinished, the wafer W is delivered to the transfer arm 302 a. Then, thetransfer arm 302 a is raised while holding the wafer W up to the waferinspection part 301 and moved to below the holding arm 171. Then, thewafer W is sandwiched between the locking part 171 a and the movableholding part 171 b of the holding arm 171 and thereby delivered to theholding arm 171, and subjected to inspection at the wafer inspectionpart 301.

After the inspection is finished, the wafer W is delivered again to thetransfer means 302 and then delivered to the waiting and mounting table320. In parallel with that, the control unit 6 determines which of threekinds of states the state of the wafer W belongs to: a state of beingexposable in the exposure apparatus 4; a state of being unexposable inthe exposure apparatus 4; and a state of being unexposable in theexposure apparatus 4 under the existing condition but becoming exposablein the exposure apparatus 4 by re-cleaning in the wafer cleaning part300.

As a result of the inspection at the wafer inspection part 301, when itis determined that the wafer W is in a state of being exposable in theexposure apparatus 4, the wafer W on the waiting and mounting table 320is transferred out of the cleaning and inspection unit 310 andtransferred to the dehydration unit 102. Further, also when it isdetermined that the wafer W is in a state of being unexposable, thewafer W is transferred out of the cleaning and inspection unit 310 andthe subsequent treatments on the wafer W are stopped.

When the inspection result of the wafer W is “re-cleaning,” the wafer Won the waiting and mounting table 320 is transferred by the transfermeans 302 again to the wafer cleaning part 300. The wafer W transferredagain to the wafer cleaning part 300 is subjected again to theabove-described cleaning and inspection, and the re-cleaned andre-inspected wafer W is transferred out of the cleaning and inspectionunit 310 and transferred to the dehydration unit 102. The subsequentsteps S12 to S15 are the same as those in the above-described embodimentand therefore the description thereof will be omitted.

According to this embodiment, the wafer cleaning part 300 cleaning therear surface of the wafer W and the wafer inspection part 301 inspectingthe cleaned wafer W are housed in the same casing 303, and the transferof the wafer W between the wafer cleaning part 300 and the waferinspection part 301 can be performed by the transfer means 302 providedinside the casing 303. Therefore, for transferring the wafer W betweenthe wafer cleaning part 300 and the wafer inspection part 301, itbecomes unnecessary to use the wafer transfer apparatus provided, forexample, outside the casing 303, namely, in the interface station 5 asin the prior art. As a result, the wafer transfer distance in thecoating and developing treatment system 1 can be reduced and the load onthe wafer transfer apparatus in the interface station 5 can be reduced.

Further, since the transfer of the wafer W accompanying the re-cleaningat the wafer cleaning part 300 is performed by the transfer means 302,the load on the wafer transfer apparatus outside the casing 303 is neverincreased in the re-cleaning. Note that the wafer inspection part 301 isarranged above the wafer cleaning part 300 in the above embodiment, butthe wafer cleaning part 300 may be arranged above the wafer inspectionpart 301 the other way round.

Further, the transfer arms are selectively used for the wafer determinedto be unexposable in the exposure apparatus 4 and the wafer W determinedto be exposable among the wafers W which have been subjected to thecleaning and inspection. In this case, it is possible to prevent a cleantransfer arm from being contaminated with particles adhering to thewafer W determined to be unexposable. Consequently, the transfer armsand the units used in the downstream steps can be kept clean.

Note that when it is determined that the wafer W is in a state of beingunexposable or requiring re-cleaning as a result of the inspection atthe wafer inspection part 301, the transfer means 302 may be cleaned atthe wafer cleaning part 300 after transferring the wafer W.

Further, the dehydration unit 102 may be provided inside the cleaningand inspection unit 310. In this case, for example, the dehydration unit102 is arranged inside the casing 303 in place of the waiting andmounting table 320. It is preferable to transfer, after the inspectionat the wafer inspection part 301, the wafer W to the dehydration unit102 and to perform dehydration treatment on the wafer W. This makes itpossible to perform the dehydration treatment in parallel while waitingfor the inspection result of the wafer W, thus improving the throughputof the wafer W.

Further, the temperature regulation performed in the temperatureregulation unit 112 in the above embodiment may be performed, forexample, inside the cleaning and inspection unit 310. In this case, acooling mechanism 400 cooling, for example, the air inside the casing303 is provided at a ceiling part of the casing 303 of the cleaning andinspection unit 310 as illustrated, for example, in FIG. 18, and thecooling mechanism 400 regulates the temperature of the atmosphere insidethe casing 303 to a predetermined and thereby performs temperatureregulation of the wafer W. For the cooling mechanism 400, a radiatorthrough which coolant at a predetermined temperature flows can be used.This enables temperature regulation of the wafer W during the time whenthe wafer W is kept waiting on the waiting and mounting table 320 afterthe inspection of the wafer W is finished. Consequently, the timerequired for the temperature regulation of the wafer W can be reducedand the transfer to the temperature regulation unit 112 becomesunnecessary, thus improving the throughput in the coating and developingtreatment system 1. Further, the temperature regulation unit 112 itselfbecomes unnecessary, leading to downsizing of the interface station 5.

Note that though the wafer cleaning part 300 and the wafer inspectionpart 301 are arranged in the up and down direction in the casing 303 ofthe cleaning and inspection unit 310 in the above embodiment, thearrangement of the wafer cleaning part 300 and the wafer inspection part301 is not limited to that in this embodiment. For example, asillustrated in FIG. 19, the wafer cleaning part 300 and the waferinspection part 301 may be arranged in the horizontal direction. In thiscase, the transfer of the wafer W between the wafer cleaning part 300and the wafer inspection part 301 may be performed by moving the framebody 144, for example, with the wafer W held on the suction pads 140 ofthe wafer cleaning part 300. Then, the rear surface of the wafer W heldon the suction pads 140 is inspected by the light source 172 and thecamera 173.

Further, the wafer W may be held on the suction pads 140, for example,until the inspection result of the rear surface of the wafer W isavailable. This eliminates the need to transfer the wafer W to thewaiting and mounting table 320 and therefore eliminates the necessity ofnot only the waiting and mounting table 320 but also the transfer means302. In the re-cleaning, the wafer W held on the suction pads 140 ismoved to the wafer cleaning part 300, and after the cleaning, the waferW held on the suction pads 140 is moved again to the wafer inspectionpart 301. Further, when the wafer W is determined to be exposable orunexposable, the wafer W is delivered to the raising and lowering pins152 of the wafer cleaning part 300 and transferred out of the cleaningand inspection unit 310 by the wafer transfer mechanism 120. In thiscase, the suction pads 140 supported on the frame body 144 serve as thetransfer means of this embodiment.

Preferred embodiments of the present invention have been described abovewith reference to the accompanying drawings, but the present inventionis not limited to the embodiments. It should be understood that variouschanges and modifications are readily apparent to those skilled in theart within the scope of the technical spirit as set forth in claims, andthose should also be covered by the technical scope of the presentinvention. The present invention is not limited to the embodiments butmay take various forms. The present invention is also applicable to thecase where the substrate is a substrate other than the wafer, such as anFPD (Flat Panel Display), a mask reticle for a photomask or the like.

What is claimed is:
 1. A substrate treatment system comprising atreatment station in which a plurality of treatment units each treatinga substrate, and an interface station delivering the substrate betweensaid treatment station and an exposure apparatus provided outside, saidinterface station comprising: a cleaning unit cleaning at least a rearsurface of the substrate before the substrate is transferred into saidexposure apparatus; an inspection unit inspecting the rear surface ofthe substrate whether the substrate is exposable, before the substrateis transferred into said exposure apparatus; a buffer housing parttemporarily housing the substrate which has been inspected in saidinspection unit, wherein the buffer housing part is provided between thecleaning unit and the inspection unit; and a substrate transfermechanism including an arm transferring the substrate among saidcleaning unit, said inspection unit, and said buffer housing part,wherein said buffer housing part houses the inspected substrate until aninspection result of the inspected substrate is available.
 2. Thesubstrate treatment system as set forth in claim 1, wherein saidsubstrate transfer mechanism includes a first transfer arm transferringthe substrate transferred into said interface station to said cleaningunit, and a second transfer arm transferring the substrate which hasbeen cleaned in said cleaning unit to said inspection unit andtransferring the substrate which has been inspected in said inspectionunit to said buffer housing part.
 3. The substrate treatment system asset forth in claim 1, wherein said substrate transfer mechanism includesa first transfer arm transferring the substrate transferred into saidinterface station to said cleaning unit, a second transfer armtransferring the substrate which has been cleaned in said cleaning unitto said inspection unit, and a third transfer arm transferring thesubstrate which has been inspected in said inspection unit to saidbuffer housing part.
 4. The substrate treatment system as set forth inclaim 1, wherein said cleaning unit is provided on either a front sideor a back side in said interface station, wherein said inspection unitis provided on a side opposite to said cleaning unit, and wherein saidbuffer housing part is provided between said cleaning unit and saidinspection unit.
 5. The substrate treatment system as set forth in claim2, wherein said cleaning unit is provided on either a front side or aback side in said interface station, wherein said inspection unit isprovided on a side opposite to said cleaning unit, and wherein saidbuffer housing part is provided between said cleaning unit and saidinspection unit.
 6. The substrate treatment system as set forth in claim1, wherein said cleaning unit is provided on either a front side or aback side in said interface station, wherein said inspection unit isprovided on a side opposite to said cleaning unit, wherein said bufferhousing part is provided at multiple tiers in an up and down directionbetween said cleaning unit and said inspection unit, wherein said firsttransfer arm is provided to be movable along the up and down directionbetween said cleaning unit and said buffer housing part, and whereinsaid second transfer arm is provided to be movable along the up and downdirection between said inspection unit and said buffer housing part. 7.The substrate treatment system as set forth in claim 2, wherein saidcleaning unit is provided on either a front side or a back side in saidinterface station, wherein said inspection unit is provided on a sideopposite to said cleaning unit, wherein said buffer housing part isprovided at multiple tiers in an up and down direction between saidcleaning unit and said inspection unit, wherein said first transfer armis provided to be movable along the up and down direction between saidcleaning unit and said buffer housing part, and wherein said secondtransfer arm is provided to be movable along the up and down directionbetween said inspection unit and said buffer housing part.
 8. Thesubstrate treatment system as set forth in claim 1, further comprising:a temperature regulation mechanism regulating a temperature of thesubstrate which has been inspected in said inspection unit and will betransferred into said exposure apparatus, to a predeterminedtemperature.
 9. A substrate transfer method in a substrate treatmentsystem comprising a treatment station in which a plurality of treatmentunits each treating a substrate, and an interface station delivering thesubstrate between the treatment station and an exposure apparatusprovided outside, the interface station comprising: a cleaning unitcleaning at least a rear surface of the substrate before the substrateis transferred into the exposure apparatus; an inspection unitinspecting the rear surface of the substrate whether the substrate isexposable, before the substrate is transferred into the exposureapparatus; a buffer housing part temporarily housing the substrate whichhas been inspected in the inspection unit, wherein the buffer housingpart is provided between the cleaning unit and the inspection unit; anda substrate transfer mechanism including an arm transferring thesubstrate among the cleaning unit, the inspection unit, and the bufferhousing part, wherein the substrate whose rear surface has been cleanedin the cleaning unit is transferred by the substrate transfer mechanismto the inspection unit, then transferred by the substrate transfermechanism to the buffer housing part, and housed therein until aninspection result in the inspection unit is available.
 10. Anon-transitory computer-readable storage medium storing a programrunning on a computer of a control unit controlling a substratetreatment system to cause the substrate treatment system to execute themethod of transferring a substrate as set forth in claim 9.